1. Technical Field
The present application relates to a milling cutter, in particular for machining light alloy metals, with a shaft and a milling head. The milling cutter can also have a sleeve-shaped shaft with an internal chip evacuation channel that is located essentially symmetrical to the longitudinal axis of the milling cutter and a suction aperture. The milling head is held so that it is coaxial to the longitudinal axis of the tool and to the shaft, with a face cutting edge and a peripheral cutting edge as cutting edges.
2. Background Information
Workpieces made of light alloy metals, such as magnesium alloys, for example, are frequently machined using metal removing processes. In this case, however, the formation of mixtures of magnesium dust and air is a problem. This problem occurs in particular during the dry cutting of light alloy metals. To address this problem, DE 44 39 114 A1, for example, discloses a very complex method and a device for dry, metal-removing machining, i.e. machining without a coolant feed, of a workpiece that is made of light alloy metal, whereby the cutting tool is located in a closed machining chamber in which a pressure gradient is set so that during the cutting process the machining chips are removed from the machining chamber. This chip removal device takes up a very large amount of space. The high cost and level of complexity of the apparatus results from the risk of explosion which is particularly great because of the formation of dry magnesium chips and dusts.
However, a risk of explosion during the metal-removing machining of light alloy metal cannot be prevented even by the use of coolants and lubricants. Aqueous emulsions cannot be used as cooling lubricants because magnesium would react chemically with the water during the machining operations. Therefore the cooling lubricants used must be oil-based. These cooling lubricants, however, have the disadvantage that the oil mist which is formed can be explosive, alone or in combination with light-alloy metal dust. An additional problem is the health hazard presented by the aerosols that are formed during machining. The cooling lubricant is also difficult and expensive to reprocess or dispose of after it has been used. Another problem, for example, is presented by the light alloy dust that is deposited on the machine tool or in the vicinity of the machine tool, which creates a risk of explosion not only immediately during the machining process but also when the dust is stirred up at some later time. Thus the specific problems related to the cutting of light alloy metals, in particular magnesium and magnesium alloys, cannot be eliminated even by the use of cooling lubricants.